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https://dev.mysql.com/doc/refman/9.7/en/hash-joins.html
It is possible to control whether hash joins are employed using one of the BNL and NO_BNL optimizer hints, or by setting block_nested_loop=on or block_nested_loop=off as part of the setting for the optimizer_switch server system variable. Memory ...
https://dev.mysql.com/doc/refman/9.7/en/ibd2sdi.html
ibd2sdi can be run on file-per-table tablespace files (*.ibd files), general tablespace files (*.ibd files), system tablespace files (ibdata* files), and the data dictionary tablespace (mysql.ibd). ibd2sdi can be used at runtime or while the server ... ibd2sdi is a utility for extracting serialized dictionary information (SDI) from InnoDB tablespace ...
https://dev.mysql.com/doc/refman/9.7/en/information-schema-routines-table.html
CHARACTER_SET_CLIENT The session value of the character_set_client system variable when the routine was created. COLLATION_CONNECTION The session value of the collation_connection system variable when the routine was created. The ROUTINES table ...
https://dev.mysql.com/doc/refman/9.7/en/information-schema-statistics-table.html
The information_schema_stats_expiry system variable defines the period of time before cached table statistics expire. Note If the innodb_read_only system variable is enabled, ANALYZE TABLE may fail because it cannot update statistics tables in the ...The MySQL column list is similar to what SQL Server 2000 returns for sp_statistics, except that QUALIFIER and OWNER are replaced with CATALOG and SCHEMA, ...
https://dev.mysql.com/doc/refman/9.7/en/information-schema-triggers-table.html
CHARACTER_SET_CLIENT The session value of the character_set_client system variable when the trigger was created. COLLATION_CONNECTION The session value of the collation_connection system variable when the trigger was created. To see information ...
https://dev.mysql.com/doc/refman/9.7/en/mrr-optimization.html
Two optimizer_switch system variable flags provide an interface to the use of MRR optimization. For MRR, a storage engine uses the value of the read_rnd_buffer_size system variable as a guideline for how much memory it can allocate for its buffer.
https://dev.mysql.com/doc/refman/9.7/en/optimizer-issues.html
MySQL uses a cost-based optimizer to determine the best way to resolve a query. In many cases, MySQL can calculate the best possible query plan, but sometimes MySQL does not have enough information about the data at hand and has to make ...
https://dev.mysql.com/doc/refman/9.7/en/replica-sql-thread-states.html
Set the terminology_use_previous system variable with session scope to support individual functions, or global scope to be a default for all new sessions. Waiting for Slave Workers to free pending events Waiting for Replica Workers to free pending ... The following list shows the most common states you may see in the State column for a replication SQL thread on a replica ...
https://dev.mysql.com/doc/refman/9.7/en/replication-administration-skip.html
When you issue the START REPLICA statement for the next time following this SET statement, the new value for the system variable sql_replica_skip_counter is applied, and the events are skipped. That START REPLICA statement also automatically sets ...
https://dev.mysql.com/doc/refman/9.7/en/replication-features-max-allowed-packet.html
On a multi-threaded replica, ensure that the system variable replica_pending_jobs_size_max is set to a value equal to or greater than the setting for the max_allowed_packet system variable on the source. max_allowed_packet sets an upper limit on ...